Thermostatic control



Patented Sept. 27, 1927.

UNITED STATES HERBERT J. SAUVAGE, OF CHICAGO, ILLINOIS,

1,643,858 PATENT OFFICE.

ASSIGNOR T0 TRUSTEES OF THE ELEC- TRO THERMOSTATIC CONTROL COMPANY, A TRUST ESTATE, OF CHICAGO, ILLINOIS.

THERMOSTATIC CONTROL.

Application filed January 7, 1924. Serial No. 684,858.

This invention relates to controlling mechanism for a gas furnace, and particularly to a gas furnace of the type employed in dwelling houses, stores, and like places.

The object of the invention is the provision of means automatically controllable from a distant point for turning off and turning on and lighting the gas, and which will insure that the gas is not turned on until the igniter is heated to the igniting point. a

One of the features of the invention resides in the electric heat motor which furnishes the power for actuating the valve through which gas is supplied to the furnace.

Another feature of the invention resides in the provision of means whereby the igniting current is sup lied to the igniter coil after the current to die heat motor has been interrupted.

Other features and advantages will appear from time to time as the description of v the invention progresses.

It is believed that the invention will be understood most readily from a detailed descriptionthereof taken in connection with I the accompanying drawings, in which tially on the line Figure 1 is a side view of the controlling equipment, except for the thermostat;

Figure 2 is a cross sectional view substan- 22 ofFigure 1;

Figure 3 is a plan view looking into the furnace fire-box, and showing the burners and igniters therein;

Figure 4 is a view substantially on the line 4-4 of Figure 3, looking in the direction of the arrows and showing the structure of one of the igriiters, and t Figure 5 is a diagram 'showing the electrical circuits for controlling the apparatus.

Referring now to the drawings, in which like reference characters indicatelike parts in the several views, 10 indicates an L-shaped bracket, the horizontal flange 11 of which is perforated to receive the upwardly extending edge 12 of a valve housing. The valve is retained 1.3 which is screw threaded into the edge 12 and overlies the flange 11. At 14 is indicated a pipe which extends from a source of gas under pressure and terminates in the valve housing. At 15 is indicated the pipe which extends to the furnace burners an supplies gas thereto.

in position by means of the cap d cated at 41 and 42.

Intermediate of the pipes 14 and 15 is a partition having a valve seat 16 therein. Arranged to engage the seat 16 is a movable valve member 17 carried by the valve rod 18 which passes slidably through the cap 13. The cap 13 has a valve seat 19 with which ,co-operates the valve disc 20 also fixed to the valve rod 18. As hereinafter more fully described, the means for operating the valve rod 18 are so constructed as to maintain either valve disc 17 or 20 in engagement with its respective valve seat. Thus, when the valve rod is moved upwardly to permit the passage of gas from the pipe 14 to the pipe 15, the disc 20 will be in engagement with the valve seat 19. This structure obviates the use of packing about the valve rod 18, and further .efll'ectively prevents the escape of gas into the atmosphere from the valve housing.

Pivotally supported on the pivot 21 is a lever 22. Pivotally joined to the lever 22 at 23 is a pair of links 24 and 25. Pivotally joined to the upper end of the valve rod 18 1s a pair of links 26 and 27. The outer ends of the links 26 and 27 are pivotally joined to the outer ends res ectively of the links 24 and 25 by means 0 the pivots 28 and 29. A tension coil spring 30 joins the pivots .28 and 29 and normally tends to limit the distance which the said pivots will move from each other.

At 31 is indicated a sylphon, the upwardly extending neck 32 of which extends through an opening in the horizontal flange 33 of an L-shaped bracket secured to the bracket member 10 by means of the screws 34. In, external screw threaded engagement with the neck 32 is a collar 35 towhich is snugly secured the sleeve or cylinder 36 of some thin material which is a good conductor of heat. Copper having a thickness of approximately 1/64 has been found to be satisfactory. The upper end of the sleeve or cylinder 36 is closed by means of the perforated cap 37 provided with a closure screw 38.

Positioned about the sleeve 36 is a thin layer of mica or other satisfactory electrical insulating material which is a fair conductor of heat, and arranged helicall about the layer of mica 39 is the wire 40 o the heating element, the terminals of which are indi Positioned below the'lever 22 1s a bracket pass slidably through member 43 arranged to support the compression coil spring 44. A rod 45 has its upper end in engagement with the lower side of the lever 22 and its lower end arranged to the horizontal flange of the bracket member 43. Fixed to the rod 45 is a disc 46 engaged by the upper end of the spring 44. This arrangement tends to maintain the lever 22 substantially in the position indicated in Figure l. p A block 47 is pivotal- 1y supported on the pin 48 in such a manner that it normally counterclockwise direction, as viewed in F igure 1. In the operation of the device, the tip 49 of lever 22 is arranged to engage under the shoulder 50 on block 47 and be thereby retained in its displaced position. Fixed to the block 47 andextending laterally to the right therefrom, as viewed in Figure 1, is a finger 51 which, when engaged by the core 52 of the solenoid 53, acts to rotate the block 47 in a clockwise direction to release the lever Pivotally supported on the pin 54 is a disc 55 carrying the curved tube 56 of a mercury switch provided with two pairs of contacts 5758 and 5960 respectively.

Fixed to the lower end of the core 52 of the solenoid 53 and extending downwardly therefrom is a rod or wire 61, the lower end of which is provided with an enlarged head 63. Projecting laterally from the disc 55 into the path of the head 63 is a pin 64. This arrangement permits the solenoid 53 to rotate the disc 55 in a counterclockwise direction to cause the mercury globule 65 to run to one end or the other of the tube 56.

In Figure 3, 66 indicates the furnace burners, each of which is provided with a mixing jet 67. Positioned between the third burners from each end are the ignition devices 68 which may be of exactly the same construction. Each ignition device comprises the insulating support 69 provided with an umbrella-like cap 70, a helically arranged heating element 71 being coiled about the insulated element 69 above the burners 66. Conductors 72 and 73 which pass upwardly through the insulating element 69 are arranged to supply current to the heating coil 71.

Referring now to the diagram in Figure 5, 74 indicates a thermostatic sylphon rigidly supported on the bracket 75. The upper end of the sylphon is provided with a projection 76 to which is pivotally secured at 77 a lever 78, the outer end of the lever 78 being mounted on the fixed pivot 79. At 80 and 81 are shown contacts which may be forced into engagement by the .free end of the lever 78. The sylphon 74 is filled with an expansible gas and is so adjusted that at a certain temperature, it will expand sufficiently to permit the separation of the contacts 80 and 81, but. upon decrease of temperature it will contends to rotate slightly in a second and tract and cause the lever 78 to force contact 81 into engagement with contact 80.

It is to be understood that the thermostat embodying the sylphon 74 and. associated members may be located at any point remote from the furnace. It is also to be understood that some other type of thermostat may be substituted for. the one herein disclosed.

The operation of the controlling mechanism will now be described.

We will assume, first, that the furnace is notin operation, in which case the controllingmechanism will be substantially in the pos tion indicated in Figure 1. In this position, the valve 1617 will be closed and the globule 65 of the mercury switch will be, in lntermediate position, and both pairs of contacts 57-58 and 5960 will be electrical a point such that contact 81 engages contact 80, a circuit will be closed from a source of current through conductor 82, contacts 80 and 81, the windingof solenoid 53, and back through another conductor 83 to the source of current. The solenoid 53 will become energized and core 52 Will be drawn up and will act through rod 61 to rotate the disc 55 "of the mercury switch in a counterclockwise direction, as seen in Figure 1. The contacts 5758 will now be electrically olned by the mercury coil 40 of the heat motor, conductor 85, contacts 58-57, conductor 86, the coils 68 of both igniters in series, conductor 87, to con ductor 83. f I

It may be here explained that the sylphon and the sleeve 36 are substantially filled with some liquid, as alcohol, which rapidly volatilizes at a comparatively low temperature. Due to the fact that the sleeve 36 is formed of a thin layerof conducting metal and is separated from the heating coil 40. by merely a thin layer of mica or similar substance, the liquid within the sleeve 36 is rapidly heated and within a very short time reaches the boiling point. As soon as the liquid begins to boil, the formation of gas causes the sylphon 31 to be expanded materially, thus forcing the The current flowing in the circuit last described acts also to heat the igniting coils 68. The screw cap or closure 38 at the upper end of the sylphon structure permits the liquid to be readily placed therein and also permits theadjustment of the contents of the sylphon to a point such that the sylphon will not be expanded materially before the coils 68 have been heated to the igniting point.

As the lever 22 moves downwardly, the pivot points 28 and 29 of the link structure also move downwardly, but the downward lever 22 downwardly.

movement of the valve rod 18 is prevented. As soon as the pivots 28 and 29 have moved downwardly beyond the pivot 89 joining the inner ends of links 26 and 27 the spring acts to draw the pivots 28 and 29 toward each other, thereby quickly snapping the rod 18 upwardly and bringing the valve 20 into engagement with valve seat 19. This permits gas to fiow to the burners 66 where it will be ignited by the'igniters 68 which have previously been heated to the igniting point, as above described.

As the left end of the lever 22 (Figure 1) moves downwardly, the lug 90 carried thereby will engage the pin 64 projecting from the disc 55 and will rotate the mercury switch in a clockwise direction, as seen in Figure 1, causing contacts 59 and 60 to be electrically connected. A circuit will now exist which extends from the conductor 82 through the resistance 91, contacts 59-60, conductor 86, igniting coils 68, and conductor 87 to conductor 83. This circuitis the same as last previously described, except the resistance 91 has been substituted for the coil 40 of the heat motor. Thus, the igniter coiis 68 will continue to be heated to the 'the left end of the lever 22 igniting point while the contents of the sleeve 36 of the heat motor are cooling. As the sylphon 31 of the heatmotor contracts,

will move upwardly until its point 49 engages the shoulder 50 on block 47, and will be maintained in this position. It is understood that during the whole operation thus far described, current will be flowing through the solenoid 53, the core 52 of which will be urged upwardly. When the lever 22 moved downwardly, the core 52 was drawn partially out of the solenoid 53 whenthe disc 55 was rotated. As the lever 22 moves upwardly :upon contraction of the sylphon 31, the disc 55 will be rotated in a counterclockwisedirection by the solenoid 53 until it reaches the neutral f or mid position shown in Figure 1, where it will be maintained by the downwardly depending lug on lever 22 so long as the point 49 of the lever is maintained under the shoulder 50. The apparatus will be maintained in the position just describedas long as the furnace is in operation.

As soon as the temperature about the thermostat 74 rises to a point such that contacts and 81'become separated, the circuit for the solenoid 53 will be broken and the core 52 will drop, striking the finger 51 which extends laterally from block 47 and rotating said block in a clockwise direction, thus releasing the lever 22 which will be returned to its normal position by means of the spring 44.

By the means above described, the supply of gas to the furnace burners and of current to the igniter coils may be so controlled from i a distant point that there is no danger of the have been heated to the gas being turned on before the igniter coils ignition point.

\Vhile in the above description and in the drawings but a single set of details has been shown, it is to be understood that applicant contemplates modifications in certain of these details, and the invention, therefore, should be limited merely by the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is? 1. In controlling mechanism for gas turnaces, a valve, an igniter element, a solenoid having a winding, contacts controlled by said solenoid, a coil, a remotely positioned thermostat, a circuit controlled by said thermostat including said winding, a circuit controlled by said solenoid contacts including said igniter and coil, an arm actuated by said coil, and means associated with said arm for opening said valve and said solenoid contacts.

2. In controlling mechanism for gas furnaces, a valve, an electric igniter, a solenoid having a winding, contacts controlled by said solenoid, a coil, a thermostat, a circuit controlled by said thermostat including said winding, a circuit for closed by said solenoid contacts, an arm actuated by said coil, means whereby said arm upon actuation will open said valve and said solenoid contacts, a second pair of contacts, a resistance, means whereby the operation of said arm closes said second pair of contacts, and a circuit controlled by said second contacts including said resistance and igniter.

I 3. A valve operating means of the class described comprlsing a valve, a pivoted lever, a connection between said valve and lever, electrically operated means for moving said lever in one direction, a sprlng for restoring the lever, a circuit for said electrically operated means and including a normally open switch, a separate circuit including a thermostat and electromagnetic means for closing said switch, said lever being arranged to open said switch and a latch for holding said lever after bein'g moved by said electrically operated means, said electromagnetic means being arranged to release said latch when the electromagnetic means is de-energized.

4. A valve operating means of the class described, comprising a valve, a lever for operating said valve, a spring for supporting said valve, electrically operated means for moving the lever against the action of the spring to open the valve, an electrical ignition device, a two-way switch for controlling the operation' of said electrically operated means and said ignition device, a circuit including a thermostat and electromagnetic means for operating said switch in one direction to energize said ignition device and first mentioned means, said lever being arranged to operate said switch in the opposite direction,

said igniter and coil means for latching said lever when moved against the action of the spring being adapted to reverse the position of said switch to disconnect the first mentioned means and to energize said ignition device, and a latch foinholding the lever when moved against the section of said spring, said electromagnetic means being adapted when deenergized to release said latch.

5. In a valve operating means of the class described, a heat motor comprising an expandible and contractible bellows containing a fluid, a circuit for heating the fluid, a switch for controlling the circuit, a valve means for connecting the valve and the switch-to the motor for operation, a catch for holding the switch open, and thermostatic means for releasing the catch.

6. In a valve operating means of the class described, a heat motor comprising a flexible bellows containing a fluid, a circuit for heating the fluid to expand the bellows, a valve and a switch operated by the motor, said switch controlling the heating circuit and open whenthe bellows is heated and expanded, a catch for holding the switch .open, and thermally operated means for releasing the catch.

In witness whereof, I hereunto subscribe my name this 4th day of January, 1924.

' HERBERT J. S AUVAGE, 

